// 笔试强训day35:计算字符串的编辑距离

#include <iostream>
#include <vector>
using namespace std;

int main() {
    string str1, str2;
    cin >> str1 >> str2;
    int n = str1.size(), m = str2.size();
    vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
    for(int i = 1; i <= n; i++) dp[i][0] = i;
    for(int j = 1; j <= m; j++) dp[0][j] = j;

    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= m; j++)
        {
            if(str1[i - 1] == str2[j - 1])
                dp[i][j] = dp[i - 1][j - 1];
            else
                dp[i][j] = min(min(dp[i - 1][j], dp[i][j - 1]), dp[i - 1][j - 1]) + 1;
        }
    }
    cout << dp[n][m] << endl;
}